Title :
ZCS based soft switched inverter at the output stage of an UPS. An alternative to PWM inverter
Author :
Muthuramalingam, A. ; Sastry, V.V.
Author_Institution :
Dept. of Electr. Eng., Indian Inst. of Technol., Madras, India
Abstract :
The present work proposes the DC link series resonant concept for DC to AC power conversion. The inverter is ZCS-based and operated at 50 kHz and above. A decoupled current control (DCC) strategy of DC link current from the load current is identified. DCC and the elevated switching frequency of the inverter enable the application of the pulse density modulation (PDM) technique to control the current and voltage of the inverter. With a simple control circuitry, the output voltage is maintained to be sinusoidal with total harmonic distortion (THD) less than 3% and with its regulation less than 0.9% for all ranges of loads and types including nonlinear and transient. This paper discusses the operation and control implementation of the proposed inverter. Inverter operation and its control strategy are verified through simulation and the results show that inverter characteristics are attractive for an UPS application with a total digital control
Keywords :
DC-AC power convertors; control system analysis; control system synthesis; electric current control; harmonic distortion; insulated gate bipolar transistors; invertors; power bipolar transistors; power conversion harmonics; power semiconductor switches; resonant power convertors; switching circuits; uninterruptible power supplies; voltage control; DC link series resonant invertor; THD; UPS output stage; ZCS; control design; control simulation; control strategy; current regulation; digital control; pulse density modulation; soft switched inverter; total harmonic distortion; voltage regulation; zero current switching; Circuits; Current control; Power conversion; Pulse inverters; Pulse modulation; Resonance; Switching frequency; Uninterruptible power systems; Voltage control; Zero current switching;
Conference_Titel :
Power Electronics and Drive Systems, 1999. PEDS '99. Proceedings of the IEEE 1999 International Conference on
Print_ISBN :
0-7803-5769-8
DOI :
10.1109/PEDS.1999.792860
